function areOnTheSameSide = ...
        are_metabolites_on_one_side_of_equation(aMetabolite, bMetabolite, equation)
    iSaMetaboliteOnLeft = false;
    iSbMetaboliteOnLeft = false;

    if regexp(equation(1: regexp(equation, '<=>')-1),aMetabolite) > 0
         iSaMetaboliteOnLeft = true;
    end
    if regexp(equation(1: regexp(equation, '<=>')-1),bMetabolite) > 0
         iSbMetaboliteOnLeft = true;
    end
    areOnTheSameSide = iSaMetaboliteOnLeft == iSbMetaboliteOnLeft;
end